MACEDON BREAKAWAY.
WHY DID THE BRAKES FAIL?
Points for Investigation
The railway authorities were not inclined yesterday to discuss the accident which resulted in the death of the guard Edward Evans near Macedon early on Saturday morning when a goods train broke in halves, causing the rear portion to run back on a gradient and collide with another goods train travelling behind.
The chairman of Railways Commissioners (Mr H. W. Clapp) is absent in Sydney for a few days, and the commissioner in charge of goods transportation (Mr C. Miscamble) is at Lakes Entrance on his annual holiday vacation. In any case, the result of the departmental inquiry will not be divulged until the coroner's inquest. The members of the board of inquiry arrived in Melbourne last night from Bendigo where since Satur day afternoon they have been examining witnesses, collecting data, and inspecting the wreckage. It is understood that the board will submit its finding to Mr W M Shannon. Railway Commissioner, this morning.
Public safety demands that special inquiries shall be made into the circumstances in which the first goods train broke in two on the steep gradient, and why the Westinghouse brake failed to hold the rear portion. Discussing the accident unofficially yesterday, railway experts confessed that it was hard to assign any reason for the failure of the automatic brakes. It was pointed out that the basic principle of the invention was that the brakes were "off ' as long as pressure, amounting to about 75lb to the square inch, or about 5 'atmospheres' was applied by the pump operated by the engine. Had the various units of the brake on the rear of the train been in good order it is thought that the brake "shoes" would have instantly and automatically gripped the tyres as soon as the hose was severed and the compressed air allowed to escape. The brakes should then have remained "on" long enough for the hand brakes to have been successfully applied. It is considered possible that the brakes on several of the trucks may have been weak, and that the momentum acquired by the loaded trucks slipping backwards downhill may have increased so rapidly as to counteract the drag on the rails of the locked wheels on the other trucks
This raises another important point which it is to be hoped will be cleared up by the departmental inquiry. To what extent have the commissioners, from motives of economy, increased the loading of goods trains, and what steps have been taken to ascertain whether the couplings are strong enough to stand the extra load. With the powerful "A2" and "D.D." engines in commission on goods train work, the temptation has been to increase the tonnage of the trains to save expense. It is significant that the weight of the train winch broke in two was officially given as 624 tons. The enormous strain in starting this dead weight into motion on a rising grade is considered to have been the prime cause of the coupling breaks between the 13th and 14th trucks from the rear. The point upon which the board is required to satisfy the commissioners is whether the coupling itself was weak or whether the strain of such a heavy load was too much for the coupling, even supposing it to have been as strong as such a type might be expected to be.
The fact that twice before in the past few weeks similar mishaps have occurred in the coupling of goods trains indicates that there is reason for believing that a new and much stronger type of coupling might well be considered by the commissioners. The type that is now doing duty on all trains is the simple chain link and drawbar of mild wrought steel. There is a certain degree of "play," and consequent friction both on the link, where it lies in the coupling hook, and the drawbar, so that either may weaken quickly under the constant strain of a heavy load.
